In weaving machines for wire gauze and similar weaving material, large fabric widths, for example, fabric widths of up to 30 meters, are woven. Examples of such weaving machines are those made by TEXO AB, Sweden, and those sold on the open market under their specification.
Hitherto, proposals have regularly been made for weaving machine designs having mechanical actuating and transmission members driven from a utilized driving member/drive axle, which in turn actuated those parts in the weaving machine (reed members, shaft frames, beams, and the like) which perform the weaving machine functions. It has also been proposed to drive certain operating parts with electrical devices, for example, AC-servos. Nevertheless, the basic premise has been that the weaving machine should predominantly comprise and be driven by mechanical transmissions, for example, gear bearings, eccentrics, and the like.
There is an acute need to produce more cost effective weaving machines having a mechanically simpler construction to achieve simpler handling and installation procedures. The present invention aims, among other things, to solve this problem. Also, in the present type of weaving machines, there is a need to increase the weaving speed. Current weaving machines are able to operate, for example, at about 30 picks/min. while maintaining the required quality of the woven material. In an attempt to increase the weaving speed without sacrificing weaving quality, weaving speed increases are discussed of about 10% of the weaving speed. There is a need however to be able to increase weaving speed more substantially, for example, by 25-40% as compared with the speeds obtained in current, mechanically built weaving machines, without any sacrifice in quality. The present invention also aims to solve this problem. According to tests, the weaving machine of the present invention offers pick speeds of up to 50 picks/min.
In the present type of weaving, there is a need, in the production of wire gauze, cloth, and the like to utilize, for example, various types, thicknesses, and the like of weft threads. This requires that the pick speed or weaving machine speed be varied as the weaving progresses. It is necessary to be able to vary, for example, the butting or beating speed, shaft frame motions, and the like. In a mechanical arrangement, one would then have started from the lowest motion pattern in the weaving machine, resulting in the weaving machine, which for certain thread types and thread thicknesses in the fabric, cloth, and the like, operates more slowly than it actually needs to for other types, thicknesses, and the like of the thread. There is therefore a need, during ongoing weaving of one and the same length of wire gauze or fabric, to be able to alter the weaving speed in a simple manner. The instant invention also solves this problem.
The same weaving machine should be able to be utilized for weaving different wire gauze types, or equivalent, requiring different weaving speeds. In a mechanical arrangement, gearwheels in clutch housings are changed in order to achieve, for example, different eccentric functions. This is a relatively awkward procedure and there is a need for more simple execution of the conversion. The present invention solves this problem.
According to the inventive concept, the driving of the main axle, or equivalent, of the weaving machine is accomplished by use of a direct-current arrangement. One or more direct-current operated units should be capable of operating as direct-current motor(s) and direct-current generator(s) and the unit or units should be driven from a power supply network to which electrical energy should also be able to be fed back. The present invention thereby solves the problem of the attainment of a small power feedback in otherwise large power consumption weaving machines.
The connections of the direct-current motor and direct-current generator functions to the power supply network should be realized without too great an interference in, and knowledge of the power supply network. The power supply network should be constituted by or connected to the public mains. The invention solves this problem also and proposes that, for the connection of the control systems between the motor and generator functions and the like, use should be made of well established components available on the market.
In order to obtain an expedient control function, it is important to utilize control signals having certain characteristics. The present invention also solves this problem and provides, among other things, that sinusoidal control signals be applied in and to the control system. The problem is solved with the adaptation of the sinusoidal form to the motions of the weaving machine. The instant invention provides that a sinusoidal form should be utilized in displaced form.
According to the inventive concept, the drive member should sometimes be accelerated and sometimes be retarded during a respective turn of the drive member, with the aid of the motor and generator functions. It is important to be able to obtain motion patterns for the shaft frames and reed members, taking into account thread material, patterns, and so forth. The present invention also solves this problem and provides that the butting speed be varied form one thread to another, from one setting to another, and the like. The motions of the shaft frames should also be able to be influenced, as well as the motions of the weaving machine in connection with the shot region.
Large forces are developed in the weaving machine due to the large masses involved. Masses of about 2000 kg/meter of weaving machine width are herein discussed. The butting force is large and needs to be effectively managed. The present invention also solves this problem and provides that the counter-force from the weave, upon abuttal or beating up, should be taken in hand and should make an active or positive contribution to the retardation path by being braked on the electrical network.
In addition, forces are needed to start lifting the frames in the butting or beating position. This should be carried out, from an energy viewpoint, in an economical manner. The present invention also solves this problem and utilizes the kinetic energy in the rotating generator unit in the lifting function.
In this type of weaving machine, it is important to be able to arrange for an emergency stop, a so-called "protector stop" which will prevent, for example, any shot in the weave. The instant invention also solves this problem since, in an emergency stop, the energy is braked on the electrical network.